1. Field of the Invention
The present invention relates to a supply liquid cartridge for reserving a supply liquid, and an image forming apparatus having the supply liquid cartridge.
2. Description of the Related Art
An ink jet printer for printing by injecting a liquid ink to a paper is provided with a printing head arranged to confront the paper, and an ink cartridge for reserving the ink to be used for the printing is generally made removable. In this printer, the ink reserved in the ink cartridge is suitably fed to the printing head and is discharged from the printing head to the paper so that an image is printed.
Here, some ink cartridge includes an ink pack enclosing the ink and a case for housing the ink pack. In a known large-sized ink jet printer, moreover, the ink in the ink pack is forcedly fed to the printing head by feeding compressed air to the inside of the case of the ink cartridge thereby to pressurize the air in that case. Therefore, the case of the ink cartridge to be used in such printer has to be gas-tight.
In order to make the case of the ink cartridge gas-tight, however, the steps of assembling the case are complicated, and a step of testing the gas-tightness has to be added after the assembly of the case is completed. Therefore, the cost for manufacturing the ink cartridge and the ink jet printer seriously rises. On the other hand, it is not easy to replace the ink pack which is housed in the gas-tight case. In case the used ink pack is taken out by once opening the case so that it may be replaced, moreover, the case has to be returned to the gas-tight state after it was housed in the case. Therefore, it takes serious troubles to use (or recycle) the case.